code: def test_viz_network():
      try:
          import graphviz
  
          for name in ["mobilenet1.0", "resnet50_v1b"]:
              net = gcv.model_zoo.get_model(name, pretrained=True)
              for shape in [(1, 3, 224, 224), (1, 3, 448, 448)]:
                  gcv.utils.viz.plot_network(net)
      except ImportError:
          pass
  
file_path: gluon-cv/tests/unittests/test_utils_viz.py
imports: from __future__ import print_function
  from __future__ import division
  import unittest
  import mxnet
  import numpy
  import gluoncv
label_desc: Use image node_id 4 for calling a global function with example usage: test_viz_network() without return types